Crystal structure of human PNP complexed with 2-mercapto(3H) quinazolinone
[PNPH_HUMAN] Defects in PNP are the cause of purine nucleoside phosphorylase deficiency (PNPD) [MIM:613179]. It leads to a severe T-cell immunodeficiency with neurologic disorder in children.  
[PNPH_HUMAN] The purine nucleoside phosphorylases catalyze the phosphorolytic breakdown of the N-glycosidic bond in the beta-(deoxy)ribonucleoside molecules, with the formation of the corresponding free purine bases and pentose-1-phosphate.
Publication Abstract from PubMed
Human purine nucleoside phosphorylase (HsPNP) is a target for inhibitor development aiming at T-cell immune response modulation. In this work, we report the development of a new set of empirical scoring functions and its application to evaluate binding affinities and docking results. To test these new functions, we solved the structure of HsPNP and 2-mercapto-4(3H)-quinazolinone (HsPNP:MQU) binary complex at 2.7A resolution using synchrotron radiation, and used these functions to predict ligand position obtained in docking simulations. We also employed molecular dynamics simulations to analyze HsPNP in two conditions, as apoenzyme and in the binary complex form, in order to assess the structural features responsible for stability. Analysis of the structural differences between systems provides explanation for inhibitor binding. The use of these scoring functions to evaluate binding affinities and molecular docking results may be used to guide future efforts on virtual screening focused on HsPNP.
Structural studies of human purine nucleoside phosphorylase: towards a new specific empirical scoring function.,Timmers LF, Caceres RA, Vivan AL, Gava LM, Dias R, Ducati RG, Basso LA, Santos DS, de Azevedo WF Jr Arch Biochem Biophys. 2008 Nov 1;479(1):28-38. Epub 2008 Aug 30. PMID:18790691
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.